A component structure with a semiconductor junction, i.e. a pn-junction, exists both in bipolar components, like diodes, bipolar transistors and IGBTs, and in unipolar components, like MOSFETs. These components differ in terms of their behaviour in conducting state. However, common to these components is that in blocking state starting from the semiconductor junction a space charge zone expands with increasing blocking voltage.
In vertical components the pn-junction is basically parallel to one of the sides of a semiconductor body. Without taking additional measures the voltage proof (maximum blocking voltage) is reduced in those areas which adjoin the pn-junction an a lateral direction. Usually this is the edge region of the semiconductor body, i.e. the region being adjacent to a side surface or edge surface, of the semiconductor body, with the edge surface running in a vertical direction between a front side and a back side of the semiconductor body. The region with the pn-junction usually forms the inner region, which is usually larger in terms of its area size than the edge region.
To increase the voltage proof in the edge region, and to therefore concentrate an avalanche breakdown in the larger inner region upon reaching a maximum blocking voltage, different edge terminations or edge structures are known. These edge terminations serve to reduce the curvature of electric field lines in the edge region when applying a blocking voltage to the component, and therefore serve to reduce the field strength in the edge region as compared to the field strength in the inner region.